2013/08/10 by Kin Chung Fong, Fong, K. C., Emma E. Wollman +13 · 3 citations
Materials Science · Physics and Astronomy · #Graphene research and applications #Thermal properties of materials #Topological Materials and Phenomena
paper · pdf · doi:10.48550/arxiv.1308.2265
The ability to transport energy is a fundamental property of the two-dimensional Dirac fermions in graphene. Electronic thermal transport in this system is relatively unexplored and is expected to show unique fundamental properties and to play an important role in future applications of graphene, including opto-electronics, plasmonics, and ultra-sensitive bolometry. Here we present measurements of bipolar, electron-diffusion and electron-phonon thermal conductances, and infer the electronic specific heat, with a minimum value of 10 k_\rmB (10-22 JK-1) per square micron. We test the validity of the Wiedemann-Franz law and find the Lorenz number equals 1.32×(π2/3)(k_\rmB/e)2. The electron-phonon thermal conductance has a temperature power law T2 at high doping levels, and the coupling parameter is consistent with recent theory, indicating its enhancement by impurity scattering. We demonstrate control of the thermal conductance by electrical gating and by suppressing the diffusion channel using superconducting electrodes, which sets the stage for future graphene-based single microwave photon detection.